GÖNÜL GÜVENÇ

Prof. Dr. GÖNÜL GÜVENÇ

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Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 June 2016 in Journal of Craniofacial Surgery
Verified
Journal Article
Closed access
GGGÖNÜL GÜVENÇ
GÖNÜL GÜVENÇ
CKCeren Kizmazoglu
Ceren Kizmazoglu
EPErcan Pinar
Ercan Pinar
AIAbdülkadir Imre
Abdülkadir Imre
IKIsmail Kaya
Ismail Kaya
NYNurullah Yuceer
Nurullah Yuceer
This retrospective study aimed to define outcomes and complications of endoscopic versus microscopic transsphenoidal surgery in pituitary adenoma. Data of 94 patients who underwent transsphenoidal endoscopic (n = 45) or microscopic surgery (n = 49) between June 2000 and June 2014 for pituitary adenoma, performed at Katip Çelebi University Hospital, were retrospectively analyzed. The patients’ symptomatology, type of adenoma, radiologic findings, surgical outcomes, and preoperative and postoperative complications were investigated. The total subtotal resection rate was 73.4% (69 patients) and partial resection rate was 26.6% (25 patients). Total subtotal resection rate was 77.6% (38 patients) in the microscopic group and 68.9% (31 patients) in the endoscopic group. Total resection was seen more often in the endoscopic group than in the microscopic group, with no significant difference between the groups. Four patients (8.2%) in the microscopic group had postoperative cerebrospinal fluid leak compared with 3 patients (6.7%) in the endoscopic group. Two patients (2.1%) had hematoma, with 1 patient each in the endoscopic and microscopic group. Panhypopituitarism development rate was higher in the endoscopic group (no significant difference between the 2 groups). One patient (2%) developed blindness in the microscopic group and 1 (2.2%) had meningitis in the endoscopic group. Based on this study, the total resection rate was higher in the microscopic group than in the endoscopic group. However, outcomes and complication rate did not differ significantly between the 2 surgical techniques. Both techniques have advantages and disadvantages. Prospective randomized controlled trials should be conducted to compare the 2 surgical methods.

8 April 2025 in Brain Sciences
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Journal Article
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GGGüven Gürsoy
Güven Gürsoy
GGGÖNÜL GÜVENÇ
GÖNÜL GÜVENÇ
Background and Objectives: This study aimed to discuss positional changes in the sternocleidomastoid (SCM) muscle and vagus nerve with head position, their effect on the surgical path, positional variations, the selection of an appropriate position for surgery, their effects on the surgical procedure, and complications by using peroperative ultrasonography. Materials and Methods: Vagal nerve stimulation surgery patients over the age of 18 years were included. Peroperative ultrasonography images were scanned, and changes in head position and anatomical and positional variations in the SCM muscle and vagus nerve at the surgical incision level were examined. Results: SCM localization was most frequently observed in the lateral aspect of the carotid sheath (n:16) in neutral position, while it was mostly observed in the medial aspect of the carotid sheath (n:16) at a 15 degree rotation. The vagus nerve was mostly observed between the jugular vein and carotid artery in neutral position (n:21), and it was observed at the same position at a 15 degree rotation (n:17). The positional change of the SCM muscle with head position was found to be statistically significant (p < 0.001), while the positional change of the vagus nerve was not (p:0.198). Conclusions: The SCM muscle closes the surgical path with head rotation by either deviating over the carotid sheath or increasing its deviation. In addition to its anatomical variations, the vagus nerve shows different positional changes with head rotation. Deciding on the head position in vagal nerve stimulation surgery, using peroperative ultrasonography rather than a routine position, may be effective in reducing surgical time and possible complications.

1 January 2018 in Turkish Neurosurgery
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Journal Article
Closed access
GGGÖNÜL GÜVENÇ
GÖNÜL GÜVENÇ
CKCeren Kizmazoglu
Ceren Kizmazoglu
MSMurat Sayin
Murat Sayin
HTHatice Sabiha Ture
Hatice Sabiha Ture
We present a case of invasive monitoring of a patient while he was being surgically treated in the status state. Our patient was a 27-year-old male who was hospitalized for frequent seizures, which began after a head trauma at the age of 3 years. Video electroencephalography was performed, and 25 clinical seizures were observed in 24 hours. Cranial magnetic resonance imaging (MRI) revealed a right frontal lesion which was hyperintense in T2-weighted and hypointense in T1-weighted images, and a subependymal nodule. For invasive monitoring, subdural electrodes were placed on the cortex surface via a right frontal craniotomy. The patient was re-operated, and the epileptic zone resection was performed. There was no sign of neurological deficit. Histopathological examination revealed cortical tuber, and the patient was scanned for tuberous sclerosis. There was no sign of tuberous sclerosis in other organs. The diagnosis of our patient was tuberous sclerosis, cortical tuber, subependymal nodule, epilepsy, and intermediate mental retardation. Radiological diagnosis should also be considered. Cortical tuber can be confused with focal cortical dysplasia. Finally, staged resection may be performed as a surgical treatment in some cases.

1 October 2018 in Journal of Craniofacial Surgery
Verified
Journal Article
Closed access
GGGÖNÜL GÜVENÇ
GÖNÜL GÜVENÇ
CKCeren Kizmazoglu
Ceren Kizmazoglu
HAHasan Emre Aydin
Hasan Emre Aydin
The primary aim of this paper is to investigate the neuroprotective and antiinflammatory effects of mannitol on optic nerve injury after acute traumatic subarachnoid hemorrhage and brain injury in rat models. Traumatic brain injury (TBI) and traumatic subarachnoid hemorrhage (tSAH) were produced by a custom-made weight-drop impact acceleration device. Thirty male Wistar rats were divided into 3 groups. Group I (n = 10) was the sham group, group II (n = 10) received TBI, and group III (n = 10) received TBI + mannitol (1 mg/kg intravenously). Optic nerve tissue glutathione peroxidase (GPx) and interleukin 1 beta (IL-1β) levels were measured 4 hours after the trauma. The authors used Kruskal–Wallis variance analysis and Mann–Whitney U tests for statistical analysis. Optic nerve tissue GPx levels were significantly higher in group III than in groups I and II (P < 0.05). Optic nerve tissue IL-1β levels were significantly lower in group III than in group II (P < 0.05) and higher than in group I (P < 0.05). Mannitol increased the antioxidant GPx levels and decreased the IL-1β levels, which can protect the optic nerve from secondary injury after severe acute trauma. Mannitol plays an important role in the treatment of acute severe indirect optic nerve injury after TBI and tSAH.

29 June 2021 in Current Medical Imaging
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Journal Article
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IKIsmail Kaya
Ismail Kaya
ICIlker Deniz Cingoz
Ilker Deniz Cingoz
MGMerve Gursoy
Merve Gursoy
MAMurat Atar
Murat Atar
GGGÖNÜL GÜVENÇ
GÖNÜL GÜVENÇ
NYNurullah Yuceer
Nurullah Yuceer
Background: Peritumoral edema of primary brain tumors is an important cause of morbidity and mortality. The number of studies currently available on the prognostic role of peritumoral brain edema in the posterior fossa is extremely limited. Objective: Based on the known importance of magnetic resonance imaging in diagnosing supratentorial metastases, this study aimed to investigate the effects of peritumoral edema on survival of patients with posterior fossa metastases and the preoperative diagnostic value of MRI. Methods: Edema and mass volumes of 49 patients with posterior fossa metastasis, who underwent surgery during 2012–2016, were measured using magnetic resonance imaging. The edema/mass indices were retrospectively calculated and interpreted by evaluating the demographic, clinical, and survival data. Results: The study consisted of 32 (65.3%) male and 17 (34.7%) female participants, with the mean age ± standard deviation of 47.25±29.25 (17–81) years. Among the 49 patients with posterior fossa metastases, 34 (69.4%) had carcinoma, while 15 (30.6%) had non-carcinoma metastases. The edema/mass indices of patients with carcinoma and non-carcinoma metastases were found to be 14.55±9.64 and 1.34±1.08, respectively, and the difference was statistically significant (p<0.001). The mean survival of patients with carcinoma and non-carcinoma metastases was found to be 642±11.52 days and 726±9.32 days, respectively; however, this difference was not statistically significant (p=0.787). Conclusion: The edema/mass ratio was found to be a significant diagnostic factor for the prediction of posterior fossa metastases. Further detailed studies are warranted to investigate the effect of edema/mass ratio on survival rate.

28 August 2025 in Muğla Sıtkı Koçman Üniversitesi Tıp Dergisi
Verified
Journal Article
Closed access
GGGüven Gürsoy
Güven Gürsoy
GGGÖNÜL GÜVENÇ
GÖNÜL GÜVENÇ
Anterior cervical microdiscectomy and fusion (ACDF) and posterior cervical foraminotomy (PCF) are frequently applied surgical approaches in cervical radiculopathies. It is planned to compare and discuss the clinical results, complications, amount of bleeding, recurrence and reoperation rates, and instability development between these two methods and examine the superiority of the techniques in this study. Patient archives were scanned and clinical and radiological documents were examined for this retrospective study. Short-term (postoperative first 24 hours) and long-term (1-6 months) changes in preoperative complaints, preoperative and postoperative functional cervical spine radiographs and cervical MRI images, presence of complications, amount of bleeding, recurrence and reoperation status were recorded. Trauma patients, patients with instability and malignancy-related pathologies, patients with multilevel surgical intervention or previous cervical spine surgery anamnesis, patients under the age of 18, and patients whose data were not available were excluded from the study. No statistically significant difference was found between the amount of bleeding, pain in the first 24 hours postoperatively, pain in the 1st month, pain in the 6th month, development of complications, recurrence and reoperation rates, and development of instability. It was observed that the surgical time of posterior foraminotomy was shorter and was statistically significant. It was observed that neither surgical technique had any obvious superiority over the other in the 6-month postoperative period. Different results can be achieved with larger sample size and longer term follow-up.